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New spectral depolarization data for single molecule rhodamine 6G scattering is presented. The wavelength-dependent properties of a hybrid molecular-metallic wave function as the Raman resonant state is outlined.

The oxidation of magnetite has been studied in solution namely, the loss of optical absorption in the near-IR region. The photoeffect on the oxidation has also been carefully studied and conclusion states that light has a very small effect on the oxidation process.

At the single-molecule level, the surface enhanced Raman scattering (SERS) from Rhodamine 6G adsorbed on small, optically resolvable aggregates of silver nanoparticles is detectable. The SERS scattering intensity fluctuations are due to the motions of the molecule in and out of the hot spot and are highly localized around it.

Single-walled carbon nanotube diodes are fabricated in a split-gate geometry with electron (n) and hole (p) regions separated by a central region. With the central region gated p or n type the diodes “leak” at low voltages, likely due to tunneling across the smaller depletion region. With the central region intrinsic, nearly ideal diode behavior is observed. Comparison to theory for a one-dimensional diode yields the band gap of the tube and the transmission coefficient through the junction. In reverse bias, the breakdown voltage depends weakly on temperature and nanotube diameter. Comparisons are made to predictions for Zener tunneling and avalanche breakdown. [ABSTRACT FROM AUTHOR]

Ultrathin metal films have a wide variety of applications, especially in microelectronics. A key method to deposit these films is plasma‐enhanced atomic layer deposition (PEALD), which is known for its ability to deposit thin films conformally and at relatively low temperatures. Building on the recent work, an improved recipe is reported on for the development of nickel PEALD technology, through which fully epitaxial nickel thin films are deposited. The effect of continuous heating on the phase structure and agglomeration in the metastable thin films is investigated in this paper. The variations of the phase structure are monitored via in situ synchrotron X‐ray diffraction, as well as optical roughness analysis. The temperature windows for phase transformation and particle formation are determined. It is noted that, after the hcp‐to‐fcc transformation and particle coalescence processes are complete, the particles reshape to acquire the thermodynamically stable shapes dictated by the Wulff theorem. Additionally, a crystallographic orientation relationship between the fcc particles and the sapphire substrate is observed, i.e., Ni (111)||Sapphire(002). Epitaxial nickel thin films are prepared via atomic layer deposition. These films have a hexagonal crystal structure, as dictated by the sapphire substrate. The nickel hexagonal phase is metastable at lower temperatures. The effect of continuous heating of the films to various temperatures is investigated, and the nature of phenomena such as phase transformation and particle formation is discussed. [ABSTRACT FROM AUTHOR]

Ultrafast photocurrent measurements are performed on individual carbon nanotube p-i-n photodiodes. The photocurrent response to subpicosecond pulses separated by a variable time delay &Dgr;t shows strong photocurrent suppression when two pulses overlap (&Dgr;t = 0). The picosecond-scale decay time of photocurrent suppression scales inversely with the applied bias VSD, and is twice as long for photon energy above the second subband E22 as compared to lower energy. The observed photocurrent behavior is well described by an escape time model that accounts for carrier effective mass. [ABSTRACT FROM AUTHOR]

There is a great interest in various branches of the advanced materials industry for the development of novel methods (and improvements to existing ones) for the deposition of conformal ultrathin metallic films. In most of these applications, like enhanced solar absorbers and microelectronics, achieving the capacity to deposit a conformal thin film on a three-dimensional structure is an important condition. Plasma-enhanced atomic layer deposition (ALD) is known for its potential for growth of conformal thin films with a precise control over the thickness and its capability for deposition at relatively low temperatures (below 500 °C). This study evaluates the potential of plasma-enhanced ALD for growth of conformal nickel thin films, using bis(ethylcyclopentadienyl)nickel and nitrogen/hydrogen plasma as precursors. A comprehensive analysis of the structure, composition, and physical properties of the films was performed. The results indicate that conformal nickel films with low levels of impurity were successfully deposited on sapphire. The films had a roughness of R a = 1.5 nm and were seen to be under strain. The deposited nickel had a hexagonal crystal structure, with a random in-plane orientation of the grains, while the grains had their c-axes oriented along the normal to the interface. These results pave the way for conformal low-temperature deposition of high-quality nickel thin films on three-dimensional structures.